深水Akpo油田防砂方案设计

Deepwater sand control design in Akpo Oilfield

Akpo油田位于尼日利亚1 150～1 750 m深水区,开发环境恶劣,出砂可能性研究、防砂方式选择及精度设计至关重要。为此,对Akpo油田多种出砂可能性和临界压差预测结果进行了对比分析:一是采用神经网络技术,预测出未取心储层的粒度特征值;二是根据粒度和泥质质量分数特性,利用中国石油大学(北京)和Tiffen方法,对该油田防砂方式和精度进行选择;三是验证室内不同的挡砂精度。研究表明,Akpo油田出砂可能性大,当初期临界压差为4 MPa时就会出砂,必须进行防砂。推荐Akpo油田主力开发储层(A储层)采用250μm优质筛管独立防砂,现场应用表明,独立防砂保证了防砂效果和产能最优化,指导了Akpo油田的开发。

Akpo Oilfield is located in the deepwater area of 1,150 to 1,750 m in Nigeria. The development environment is very had. So the prediction of sand production possibility, the selection of sand control method and the precision design are very important. In this paper, we predicted several sand production possibilities and critical sanding pressure difference of Akpo Oiffield, predicted the sand size parameters through using neural network technique for the first time, selected the sand control method and precision by using the method of China University of Petroleum and Tiffen method based on the characteristics of grain size and shale content, and finally, conducted the laboratory test to verify the different sand control precisions. Research shows that the sand production risk is very high in Akpo Oilfield and an early pressure difference of 4 MPa could lead to sand production. So sand control technique must be adopted. The 250 μm screen pipe is recommended to control the sand production independently for Layer A of Akpo Oilfield. Field application shows that this selection ensures the success of sand control and the optimal deliverability, and guides the development of Akpo Oiffield.